Christine A. Pratilas

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The kinase pathway comprising RAS, RAF, mitogen-activated protein kinase kinase (MEK) and extracellular signal regulated kinase (ERK) is activated in most human tumours, often through gain-of-function mutations of RAS and RAF family members. Using small-molecule inhibitors of MEK and an integrated genetic and pharmacologic analysis, we find that mutation of(More)
Tumors with mutant BRAF and those with receptor tyrosine kinase (RTK) activation have similar levels of phosphorylated ERK, but only the former depend on ERK signaling for proliferation. The mitogen-activated protein kinase, extracellular signal-regulated kinase kinase (MEK)/ERK-dependent transcriptional output was defined as the genes whose expression(More)
Tumors with mutant BRAF and some with mutant RAS are dependent upon ERK signaling for proliferation, and their growth is suppressed by MAPK/ERK kinase (MEK) inhibitors. In contrast, tumor cells with human EGF receptor (HER) kinase activation proliferate in a MEK-independent manner. These findings have led to the development of RAF and MEK inhibitors as(More)
The clinical efficacy of epidermal growth factor receptor (EGFR) kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here, we show, in multiple complementary models, that resistance to WZ4002(More)
Identifying the spectrum of genetic alterations that cooperate with critical oncogenes to promote transformation provides a foundation for understanding the diversity of clinical phenotypes observed in human cancers. Here, we performed integrated analyses to identify genomic alterations that co-occur with oncogenic BRAF in melanoma and abrogate cellular(More)
Hyperactivated extracellular signal-regulated kinase (ERK) signaling is common in human cancer and is often the result of activating mutations in BRAF, RAS, and upstream receptor tyrosine kinases. To characterize the mitogen-activated protein kinase/ERK kinase (MEK)/ERK dependence of lung cancers harboring BRAF kinase domain mutations, we screened a large(More)
Selumetinib (AZD6244, ARRY-142886) is a selective, non-ATP-competitive inhibitor of mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK)-1/2. The range of antitumor activity seen preclinically and in patients highlights the importance of identifying determinants of response to this drug. In large tumor cell panels of diverse lineage,(More)
Mutations in RAS proteins occur widely in human cancer. Prompted by the confirmation of KRAS mutation as a predictive biomarker of response to epidermal growth factor receptor (EGFR)-targeted therapies, limited clinical testing for RAS pathway mutations has recently been adopted. We performed a multiplatform genomic analysis to characterize, in a nonbiased(More)
BRAF(V600E) drives tumors by dysregulating ERK signaling. In these tumors, we show that high levels of ERK-dependent negative feedback potently suppress ligand-dependent mitogenic signaling and Ras function. BRAF(V600E) activation is Ras independent and it signals as a RAF-inhibitor-sensitive monomer. RAF inhibitors potently inhibit RAF monomers and ERK(More)
Melanoma is a disease characterized by lesions that activate ERK. Although 70% of cutaneous melanomas harbor activating mutations in the BRAF and NRAS genes, the alterations that drive tumor progression in the remaining 30% are largely undefined. Vemurafenib, a selective inhibitor of RAF kinases, has clinical utility restricted to BRAF-mutant tumors. MEK(More)